load capacity for winch strap

[Ralph vaughn]

My 2008 Sea Ray 290 has a dry weight of 9300# and I estimate another 1000# in fuel, water, holding tanks and miscellaneous items on the boat. So I estimate the gross weight at 10300#. What load capacity do I need for my winch strap? My trailer is a bunk style.

thanks Ralph

 

[OllieC]

I don't know for sure but I just purchased this one because I got tired of them snapping at the launch.
https://www.dutton-lainson.com/proddetail.php?prod=24247

 

[OllieC]

here's some more info

https://www.etrailer.com/question-26695.html

 

[Henry Boyd]

Ralph,

To put this in perspective. The DOT publishes recommendations for the securement of cargo in commercial vehicles. This is covered in the FMCSA’s Driver’s Handbook for Cargo Securement. The requirements in that document don’t apply to a non commercial cargo loading, but part of the material covers the over the road environment. The FMCSA has determined that in the forward direction accelerations (and resulting loads) up to 0.8g are normal in roadway movements, as well as 0.5g in either side direction and rear, as well as 0.2g vertically. This is where g is equal to the weight of the cargo. It is expressed this way because cargo objects come in different weights. Keep in mind these aren’t maximum accelerations, just the range of operating forces and higher ones can happen under the right circumstances.

What that says is with a 10,000 pound boat it can generate a 5000 pound force sliding back on the trailer under normal driving conditions. As a result, the total amount of securement would need to exceed that. In the case of the boat trailer that would be: friction needed to be overcome for boat to move, strength of bow securement, and strength of stern securement. So for driving, three (bow & two stern) 2,000 pound SWL minimum cables, or straps, would be reasonable for driving. However, stern straps are rarely used when hauling the boat up a ramp, so something on the order of the strap Ollie suggested might be in order for the bow restraint.

 

[Juliery]

It's likely you're beyond a strap and hand powered winch. I would suggest a power winch and cable rated for at least half the weight of your boat. Once the boat is winched up to the winch post hook up your heavy safety chain before driving up the ramp.

Another potential point for failure is at the bow eye. Do they even have a safe load rating when new? What about hidden corrosion after many years exposed to salt water? How good is the backing? I'll have to pull mine out to check.